SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e419649c1de4d84ec817f2453d5d3c2a3b304efe12fe191e71f1bbbbf7979db' 
  AND token = '3BhGUQ8hrUQyzWpkrFBYJS/CoCwxEzPk/cYKR2hZD6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}